Summary of the invention
One aspect of the present invention provides image processing equipment and method, and it can be used for strengthening three-dimensional (3D) effect and reduce eye fatigue being used for 3D stereo display to use the image that is obtained by many view camera.
One aspect of the present invention provides image processing equipment and method, and it can be used for the convergence (convergence) that comes the control chart picture by the parallax of adjusting image at the receiving terminal that receives and show 3D rendering.
According to one aspect of the invention, provide image processing equipment to comprise: to receive three-dimensional (3D) image and 3D rendering is divided into the image division unit of left-eye image and eye image; The histogram generation unit of the histogram (histogram) of the parallax between the corresponding units image of estimation left-eye image and eye image, the frequency of measuring the estimating disparity generation and generation parallax and frequency; Use the histogram that produces to determine the horizontal movement value determining unit of the horizontal movement value of left-eye image and eye image; Based on flatly mobile left-eye image of determining of horizontal movement value and at least one the horizontal movement unit in the eye image.
The threshold value that horizontal movement value determining unit calculated threshold and use are calculated is determined the horizontal movement value, and described threshold value makes that the estimated rate of parallax is a positive parallax in the histogram.Described estimated rate is the steady state value that is confirmed as making that at least one backward three-dimensional viewing in mobile left-eye image and the eye image has optimal depth consciousness.
Horizontal movement value determining unit can determine that corresponding to half value of threshold value be the horizontal movement value.
Thereby the horizontal movement unit can be based on the mobile left-eye image in threshold level ground and eye image and adjustment parallax.
Described equipment can further comprise user interface section, it receives estimated rate or threshold value and sends estimated rate or threshold value to horizontal movement value determining unit from the user by user input signal, and wherein horizontal movement value determining unit uses the estimated rate or the threshold value that are received to determine the horizontal movement value.Described equipment can further comprise the 3D stereoscopic display unit, and it shows from the left-eye image and the eye image of the adjusted parallax of horizontal movement unit output.
According to another aspect of the present invention, provide image processing method to comprise: to receive three-dimensional (3D) image and 3D rendering is divided into left-eye image and eye image; Parallax between the corresponding units image of estimation left-eye image and eye image is measured the frequency that estimating disparity takes place, and produces the histogram of parallax and frequency; Use the histogram that produces to determine the horizontal movement value of left-eye image and eye image; Based on the flatly mobile left-eye image of determining of horizontal movement value and in the eye image at least one to adjust parallax.The determining of described horizontal movement value comprises: calculated threshold, this threshold value make that the estimated rate of parallax is a positive parallax in the histogram; And use the threshold value of being calculated to determine the horizontal movement value.Described estimated rate is the steady state value that is confirmed as making that at least one backward three-dimensional viewing in mobile left-eye image and the eye image has optimal depth consciousness.
According to another aspect of the present invention, provide a kind of image processing equipment to comprise: image division unit, it receives image and is first image and second image with image division; The histogram generation unit, it estimates the parallax between the corresponding units image of first image and second image, measures the frequency that the parallax estimated takes place, and produces the histogram of parallax and frequency; The motion value determining unit, it uses the histogram that produces to determine the motion value of first image and second image; And moving cell, it moves in first image and second image at least one based on the motion value of determining, and, so adjust the parallax of image.Wherein, described motion value determine comprise: calculated threshold, this threshold value make that the estimated rate of parallax is a positive parallax in the histogram; And use the threshold value of being calculated to determine described motion value.Described estimated rate is to be confirmed as the steady state value that feasible at least one backward three-dimensional viewing that moves in first image and second image has optimal depth consciousness.
According to another aspect of the present invention, provide a kind of image processing method, comprising: receive image, and be first image and second image image division; Estimate the parallax between the corresponding units image of first image and second image, measure the frequency that the parallax estimated takes place, and produce the histogram of parallax and frequency; Use the histogram that produces to determine the motion value of first image and second image; And move in first image and second image at least one based on the motion value of determining, and, the parallax of image therefore adjusted.Wherein, described motion value determine comprise: calculated threshold, this threshold value make that the estimated rate of parallax is a positive parallax in the histogram; And use the threshold value of being calculated to determine described motion value.Described estimated rate is to be confirmed as the steady state value that feasible at least one backward three-dimensional viewing that moves in first image and second image has optimal depth consciousness.
According to another aspect of the present invention, provide a kind of computer-readable medium storing that has write down the program that is used for the carries out image processing method on it.
Embodiment
Now will more comprehensively describe the present invention in conjunction with the accompanying drawings, wherein show exemplary embodiment of the present.Yet the present invention can be presented as a lot of different forms and should not be interpreted as is to be limited to the embodiment that wherein sets forth; More precisely, these embodiment are provided in case this openly will be completely and completely, and send thought of the present invention to those skilled in the art fully.
The structure of the camera that produces real image (real image) is described in conjunction with Fig. 1 and 3 now.
Figure 1A-1C illustrates the type of stereoscopic camera.Figure 1A illustrates parallel stereoscopic camera.The aligning of parallel stereoscopic camera is simple.Yet, because parallel stereoscopic camera do not have convergence function, consider the people visual signature it can not photographic images.Therefore, captured image can not be as three-dimensional (3D) image.Figure 1B illustrates the toed-in stereoscopic camera.The Toed-in stereoscopic camera has convergence function, and has critically reflected people's visual signature.Yet the toed-in stereoscopic camera has the problem shown in the accompanying drawing 2.
Accompanying drawing 2 illustrates the problem that produces when using the toed-in stereoscopic camera shown in the accompanying drawing 1B to carry out shooting operation.
When rectangular object 21 was positioned between the camera axis of the left and right sides camera shown in Fig. 2, the image of taking by a left side and right camera 23 and 25 was out of shape as shown in Figure 2 respectively.When image 23 and 25 was used for 3D rendering, image 23 and 25 this distortion caused eye fatigue.
Fig. 1 C illustrates mixing (hybrid) stereoscopic camera of aiming in the mode that prevents parallel stereoscopic camera that Figure 1A and 1B illustrate respectively and toed-in stereoscopic camera shortcoming.In mixing stereoscopic camera, lens unit and charge-coupled device (CCD) unit can move individually.Therefore, can control convergence by the position of adjusting CCD unit and lens.
Fig. 3 illustrates the structure of many view camera.
The conventional method of taking multi-view image is used many view camera of structure as shown in Figure 3.Carry out in the standardization at the 3D of Motion Picture Experts Group (MPEG) audio frequency and video (3DAV), the image of the many view cameras photograph by accompanying drawing 3 is as standard picture.Stereoscopic camera can have the structure shown in the accompanying drawing 1C.Yet under the situation that multi-view video is taken, the convergence of controlling each image is actually infeasible.
Fig. 4 illustrates the application of multi-view video coding.
With reference to figure 4, the image of exporting from many view camera of being made up of N camera is compressed and stores or transmit multi-view coded processing, rebuilds in many views decodings are handled then.Reconstructed image can be according to the demonstration that should be used for of display device.That is, the image sequence of view is presented on the 2D display.For 3D stereo display, two views are selected and be used for showing 3D rendering on the 3D three-dimensional display.Show that for the many views of 3D at least two views are selected and be used for showing on the 3D multi-view display 3D multi-view image.When two image sequences were used for showing 3D rendering on the 3D three-dimensional display, the 3D three-dimensional display had the same problem of parallel stereoscopic camera shown in Figure 1A.Therefore, the image that obtains by many view camera must correctly be handled to show on the 3D three-dimensional display.
Fig. 5 A-5C illustrates according to an embodiment of the invention left-eye image and the eye image by parallel many view cameras photograph.When supposition was chosen two views and is used for 3D stereo display from the image sequence by parallel many view camera outputs, the phenomenon shown in Fig. 5 A-5C will appear.
Fig. 5 A illustrates left-eye image, and Fig. 5 B illustrates eye image.Fig. 5 C is illustrated in the left-eye image of Fig. 5 A on the eye image that is superimposed upon Fig. 5 B in the plane to show the parallax between them.Suppose that just there is positive parallax in target (objects) when eye image when being present in the right of same target of left-eye image.In this case, the image of all targets has positive parallax in the superimposed images shown in Fig. 5 C.In other words, we can say because the feature of parallel camera does not exist convergence point or convergence point to be present in outside the screen.
When the superimposed images shown in Fig. 5 C showed on the 3D three-dimensional display, the image of all targets seemed outstanding from screen in the overlapping image.This parallax, just, the degree of depth causes eye fatigue and has reduced 3D effect.
Fig. 6 A-6C illustrates according to one embodiment of present invention and produces the stable and stereoscopic treatment of picture with being moved to the left to the right respectively by left-eye image and eye image with Fig. 5 A-5C.In other words, Fig. 6 A-6C illustrates by adjusting parallax the image processing method of stablizing 3D rendering is provided to the user.Fig. 6 A illustrates the left-eye image among the accompanying drawing 5A that moves on to the right, and Fig. 6 B illustrates the eye image among the accompanying drawing 5B that moves on to the left side.Accompanying drawing 6C illustrates according to the eye image among the synthetic Fig. 6 A of the left-eye image with among Fig. 6 B of embodiments of the invention on the 3D three-dimensional display.
With reference to figure 6C, the whole parallax of synthetic image is less than the parallax of the superimposed images shown in the accompanying drawing 5C.Therefore, the image of some target, for example, the image 61 of target has negative parallax.Therefore in other words, image 61 has the negative degree of depth and looks like and is absorbed in screen.Image 64 is the convergence points that have parallax free and have the degree of depth that equals screen intensity.Image 62 and 63 parallax are positive.Therefore, image 62 and 63 looks like from screen outstanding.
When eye image and left-eye image synthesized shown in Fig. 6 C, the image of composograph internal object had the degree of depth more various than the superimposed images shown in Fig. 5 C.Therefore, can provide stable and three-dimensional more image to the user.Describe now a kind of according to an embodiment of the invention method of definite horizontal movement value, its right eye by estimating input when right eye and left-eye image are flatly mobile with predetermined space and the parallax between the left-eye image are determined the parallax histogram of the relation between horizontal movement value and the definite parallax frequency of occurrences of representing the parallax estimated in the image and estimation.
Fig. 7 illustrates according to an embodiment of the invention the disparity estimation (DE) based on piece (block-based).
With reference to the accompanying drawings 7, left-eye image is divided into the NxN piece of equal sizes.Use absolute difference and (SAD) or absolute difference average (MAD) estimate to be similar to most the piece of the eye image of corresponding piece in the left-eye image.In this case, the distance definition between benchmark (reference) piece and the estimation piece is disparity vector (DV).Usually, DV distributes to each pixel in the benchmark image.Yet, in order to reduce the amount of required calculating, approximate identical among the DV that supposes all pixels in the piece and the block-based DE.For carrying out DE to each pixel, the DV that obtains each pixel is known as DE based on pixel.
Block-based DE or be used for estimating disparity based on the DE of pixel.
Fig. 8 illustrates the histogram of parallax between the left-eye image and eye image according to an embodiment of the invention.With reference to the accompanying drawings 8, the trunnion axis of histogram is represented the parallax size, and the vertical axis of histogram is represented frequency,, has the number of unit (unit) image of identical big or small parallax that is.Cell picture represent among the block-based DE cell block and based on the unit pixel among the DE of pixel.
In the situation of the histogram shown in Fig. 8, the stable and stereoscopic image can offer user's eyes, and target seems outstanding from screen.In the histogram of Fig. 8, most of images have negative parallax, and other has a positive parallax.
Therefore, the distribution of the histogram of general stereo-picture need be adjusted to the histogram distribution of Fig. 8.
Fig. 9 A-9C illustrates three kinds of histograms of parallax between the left-eye image in the multi-view image that obtains by parallel many view camera and eye image according to an embodiment of the invention.There are various types of parallax histograms in type and some stereo-picture parameters (such as the distance between camera and the focal length) according to stereoscopic camera.The histogram of parallax can be categorized as three kinds of histograms shown in Fig. 9 A-9C between left-eye image by parallel many view cameras photograph and the eye image.The histogram of Fig. 9 A presents than higher frequency in the low zone of parallax.The zone of the histogram of Fig. 9 B in parallax is inclined to one side presents than higher frequency.The histogram of Fig. 9 C presents than higher frequency in the high zone of parallax.
Yet, as Fig. 9 A in the horizontal direction of parallel many views shown in the 9C or three-dimensional view all parallax value usually greater than zero, this be because camera aligning parallel to each other and therefore optical axis do not converge on any one point.This left eye and eye image with this histogram can cause serious eye fatigue.Stabilized frequency distribution map shown in Fig. 8 can reduce eye fatigue and be used to produce the 3D stereo-picture.
According to one embodiment of present invention, Fig. 9 A is adjusted to the hypothetical parallax histogram shown in Fig. 8 to the 3D stereo-picture histogram shown in the 9C.For this reason, accompanying drawing 9A need move up at losing side to the histogram shown in the 9C.
As mentioned above, in order to produce the input picture of the parallax histogram that has shown in Fig. 8, analyze the parallax histogram of input picture for each incoming frame, and calculate parallax threshold value Dth, described threshold values makes the estimated rate (a%) of all parallaxes in the parallax histogram of input picture for just.In this case, a is the steady state value of experimentally determining.Persons skilled in the art can be known parallax threshold value Dth and can use several different methods to calculate.
The threshold value of calculating in the histogram of Fig. 9 A is Dth1, is Dth2 in the histogram of Fig. 9 B, and is Dth3 in the histogram of Fig. 9 C.When accompanying drawing 9A to the histogram of 9C respectively by the threshold value Dth1 that calculates to Dth3 when losing side moves up, (that is a%) will be as shown in Figure 8 positive parallax, at the estimated rate of Fig. 9 A total parallax in each histogram of 9C.
In the parallax adjustment is handled, move right and eye image is moved to the left based on the threshold value left-eye image of calculating.Then, the left-eye image and the eye image that move horizontally are synthesized.The position that optimal depth consciousness is provided that is used for the convergence point of target is placed stereoscopic screen is handled in this parallax adjustment.
Figure 10 A-10C illustrates according to an embodiment of the invention based on the left-eye image of horizontal movement value and moving horizontally of eye image, and described horizontal movement value uses the parallax histogram to determine.
As mentioned above, according to present embodiment, by the parallax of parallax threshold value Dth adjustment 3D rendering, so that positive parallax occupies the a% of parallax total between left eye and the eye image.10A-10C with reference to the accompanying drawings, left-eye image moves horizontally Dth/2 to the right, and eye image moves horizontally Dth/2 left.In this case, the parallax of 3D stereo-picture is adjusted.
Figure 10 C illustrate flatly move and overlapping Figure 10 A in left-eye image and the eye image among Figure 10 B.With reference to figure 10C, superimposed images internal object 101 has negative parallax, and target 102 and 103 has positive parallax, and target 104 has parallax free.Therefore, when using the parallax of the parallax adjustment 3D rendering between left eye and the eye image, the target in the superimposed images has the different degree of depth.Therefore, can provide stable and three-dimensional more image to the user.
Figure 11 is the block diagram according to embodiments of the invention treatment of picture equipment 100.With reference to Figure 11, image processing equipment 100 comprises image division unit 11, histogram generation unit 13, horizontal movement value determining unit 15, horizontal movement unit 17 and user interface section 19.
Image division unit 11 receives 3D rendering and 3D rendering is divided into eye image and left-eye image.Then, image division unit 11 sends eye image and left-eye image to histogram generation unit 13 and horizontal movement unit 17.
The parallax that histogram generation unit 13 is estimated between eye image and the left-eye image is measured the frequency that estimating disparity takes place, and produces the histogram for parallax and frequency.In this case, can use block-based as mentioned above DE or based on DE or other method of pixel.
Horizontal movement value determining unit 15 receives the histogram that produces from histogram generation unit 13, and the horizontal movement value of definite left eye and eye image.At length, horizontal movement value determining unit 15 is analyzed the parallax histogram of each incoming frame, calculates parallax threshold value Dth, (it makes positive parallax occupy the estimated rate of total parallax, that is, a%), and determine that corresponding to half value of the parallax threshold value Dth that calculates be the horizontal movement value.
Horizontal movement value determining unit 15 can be passed through the estimated rate that user interface section 19 receives from the user, and definite parallax threshold value Dth.Perhaps, horizontal movement value determining unit 15 can directly receive parallax threshold value Dth from the user by user interface section 19.In this case, the user can import different ratios or threshold value experimentally, determines suitable horizontal movement value, and adjusts the parallax of 3D rendering so that optimum 3D effect to be provided based on the threshold value of determining.
Horizontal movement unit 17 moves right left-eye image and eye image is moved to the left the horizontal movement value that receives from horizontal movement value determining unit 15, and the left eye and the eye image of output adjusted parallax.Though not shown, parallax is adjusted equipment 100 can comprise that the 3D stereoscopic display unit is to show the left eye and the eye image of the adjusted parallax of 17 outputs from the horizontal movement unit.
Obviously left-eye image and eye image needn't move equal amount.For example, eye image can be moved, and left-eye image is not moved.
Figure 12 illustrates image processing method flow chart according to an embodiment of the invention.With reference to Figure 12,3D rendering is received and is divided into left-eye image and eye image (S120).Estimate the parallax between left-eye image and the eye image, measure the frequency of the parallax generation of estimating, and produce histogram (S122) for parallax and frequency.Determine the horizontal movement value (S124) of eye image and left-eye image based on histogram.At length, calculate the parallax threshold value, it makes the estimated rate of all parallaxes in the parallax histogram for just, and the parallax threshold value that use is calculated is determined the horizontal movement value.The horizontal movement value can be defined as equaling half of threshold value.In addition, estimated rate or parallax threshold value can be imported as user input signal by the user.
Left-eye image and eye image are horizontally moved based on the horizontal movement value of determining, and adjust the parallax (S126) between left-eye image and the eye image.The left eye and the eye image of output and demonstration adjusted parallax.
Image processing method according to an aspect of the present invention and device can be used for controlling based on the parallax between left eye and the eye image convergence of the image that obtains by many view camera, and therefore described image can be used for 3D stereo display, thereby strengthens 3D effect and reduce eye fatigue.
Image processing method according to an aspect of the present invention and device can be used for by receiving and showing the convergence (convergence) that the parallax of the receiving terminal adjustment image of 3D rendering comes the control chart picture.
The present invention can also be embodied as the embodied on computer readable code on the computer-readable medium storing.In addition, being used to finish function program of the present invention, code and code segment can be easily be explained by the technical program person in the field under the present invention.Computer-readable medium storing is any data storage device that can store thereafter by the data of computer system reads.The example of computer-readable medium storing comprises read-only memory (ROM), random-access memory (ram), CD-ROM, tape, floppy disk, optical data storage equipment and carrier wave (transmitting such as the data by the Internet).Computer-readable medium storing can also be that distributed network coupled computers system stores and carries out with distributed way so that embodied on computer readable is encoded.
Though illustrate and described the present invention especially in conjunction with exemplary embodiment wherein, yet one of ordinary skill in the art is understandable that not breaking away from the defined the spirit and scope of the present invention of claims can make different variation on form and the details.